Tip of the Tongue

Studies have shown that it happens to most people about once a week. At the
edge of your memory, an elusive word, phrase, or name hovers. You've known it
for years, yet at the moment uttering it is impossible. Frustrated, you
exclaim, "But it's right on the tip of my tongue!" The tip-of-the-tongue
experience has intrigued psychologists since the 1800s. In 1893, William James
described this irritating memory lapse: "It is a gap that is intensely active.
A sort of wraith of the name is in it, beckoning us in a given direction,
making us at moments tingle with the sense of our closeness and then letting
us sink back without the longed-for term."

Modern-day psychologists such as Donna J. Dahlgren, an assistant professor of
psychology at IU Southeast, continue to analyze tip-of-the-tongue, or TOT,
experiences. As a Ph.D. student at Kent State University, Dahlgren was
conducting experiments related to other aspects of memory when she noticed
that she was eliciting a TOT state in her subjects with many of her questions,
which were based on trivia and general knowledge. "What is the most widely
used tranquilizer in America?" was one of the questions, says Dahlgren, as was
"Which of the seven dwarfs comes first alphabetically?" Knowing that
psychologists traditionally have found it difficult to evoke TOT states
deliberately, Dahlgren decided to build a pool of such questions and then to
embark on her current study, now under way at IUS.

"I am using my general-knowledge questions to determine if there are age
differences between elderly (ages 60-80), middle-aged (ages 30-59), and young
adults (ages 18-29) that affect frequency and information available during the
TOT state," Dahlgren says. (The term "information available" refers to how
fully a person in a TOT state can describe the "longed-for term"--what it
sounds like, what it means, what its first letter is.) In previous, comparable
studies, Dahlgren says, "Elderly people have been found to be less able to
retrieve partial information, such as the first letter or a sound-alike word;
rather, the experience is described as an 'empty gap' or a state in which
'nothing will come.'" Often, however, subjects in a TOT state "are able to
retrieve partial information about the target word, but are unable to fully
retrieve the word," Dahlgren says. "They may know exactly what the word is,
but can only say that it starts with a particular letter or has a certain
sound; or they can retrieve a similar-sounding word, noting that the stated
word is not exactly what they are searching for."

These abilities suggest that the human memory stores words and their
definitions in a way that resembles a dictionary. But, Dahlgren says, "Our
mental dictionaries are much more flexible than the alphabetized version on a
bookshelf. Words can be recovered by either their meaning or their sound, and
the entries need not be examined in alphabetical order. Psychologists call
this search for a desired word 'lexical retrieval.' A TOT state appears to be
a breakdown in an intermediate stage of lexical retrieval."

This breakdown demonstrates an essential concept in the study of long-term
memory--the difference between accessibility and availability. Dahlgren
explains, "It is widely believed that long-term memories are stored somewhere
in memory, but the memories may be inaccessible--unable to be retrieved,
either temporarily or permanently. Evidence that supports the distinction
between availability and accessibility comes from the work on the tip-of-the-
tongue phenomenon."

To continue her own work on the phenomenon, Dahlgren plans to expand on the
current study. "I want to determine if exposing the subjects to the target
words prior to asking the general-knowledge questions will increase or
decrease the experimental rate of TOTs among the subjects," she says. "This
manipulation will allow me to investigate their implicit memory of the target
words and to see if more TOTs are resolved if the subjects have been recently
exposed to the target word." It is an interesting query, one of significance
to anyone who has ever tried to remember "Valium" or "Bashful" and failed.